1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
# Generated by re2py
# re2py $INPUT -o $OUTPUT
YYMAXFILL = 1
def lex(yyinput):
yycursor = 0
yylimit = len(yyinput)
count = 0
while True:
yystate = 0
while True:
match yystate:
case 0:
if yylimit <= yycursor:
return -1
yych = yyinput[yycursor]
yycursor += 1
if yych <= 0x20:
if yych <= 0x00:
yystate = 1
continue
if yych <= 0x1F:
yystate = 2
continue
yystate = 3
continue
else:
if yych == 0x27:
yystate = 4
continue
yystate = 2
continue
case 1:
# check that it is the sentinel, not some unexpected null
return count if yycursor == yylimit - YYMAXFILL + 1 else -1
case 2:
return -1
case 3:
if yylimit <= yycursor:
return -1
yych = yyinput[yycursor]
if yych == 0x20:
yycursor += 1
yystate = 3
continue
break
case 4:
if yylimit <= yycursor:
return -1
yych = yyinput[yycursor]
yycursor += 1
if yych == 0x27:
yystate = 5
continue
if yych == 0x5C:
yystate = 6
continue
yystate = 4
continue
case 5:
count += 1
break
case 6:
if yylimit <= yycursor:
return -1
yycursor += 1
yystate = 4
continue
case _:
raise "internal lexer error"
def test(str, count):
padded_str = str + (b"\0" * YYMAXFILL)
assert lex(padded_str) == count
test(b"", 0)
test(b"'unterminated\\'", -1)
test(b"'qu\x00tes' 'are' 'fine: \\'' ", 3)
test(b"'unexpected \x00 null", -1)
|
